Electronic musical instrument having keyboards

ABSTRACT

An electronic musical instrument having mainly digital circuits for producing sounds in correct musical scales as well as for producing variegated sounds and designed in this manner it may be easy to play the notes of the scales on the instrument.

Umted States Patent 11 1 11 1 3,885,489

Sasaki 4 [45] May 27, 1975 1 ELECTRONIC MUSICAL ms'rnumm 3.287.648 11/1966 Doole 328/48 HAVING KEYBQARD'S 3.288.909 11/1966- Volodin 84/ 1.01 "3.601.518 8/1971 11111 84/1.0l Inventor: F ml kl. H namaki. Jap n 3,610,800 10/1971 Deutsch 84/1101 [73] A i K u s nu Knish. 316l79ol "H9." ,Fransscn Hanamaki, Japan 1 Primary Examiner-Stephen]. Tomsky [221 1973 Assistant E.ram1'ne rU.Weldon 1 PP- 341,063 Attorney. Agent, or Firm-Browdy and Neimark 52 US. Cl. 84 1.01 841.11;841.19; 1 I l 1 3 I 1571 ABSTRACT An electronic musical instrument having mainly digital 84 circuits for producing sounds in correct musical scales as well-asfor producing variegated sounds and designed in this manner it may be easy to play the notes [56] g g z g gg of the scales on the instrument.

3.236.931 2/1966 Freeman 84/124 10 Claims, 31 Drawing Figures C 10 O UTI 3o rem-8x8 OUT-1 SHEET F s. e

PATENTED 24..Y27l975 FIG. 7

P IJENTEL 5 3.885.489

sum 7 F l G; 13

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uni. Ni. ou h XL. mh mu Ni R1. 33.. 2 b 2).. 2L 2 2L. 3 a a nun JP wmnh BL. 6 3L out R; 3; m? L n2. a. a a; JP 2 m2. 5? mm mm; 3

FUENTES W27 F975 '3 885 489 sum 1 1 FIG.18

ELECTRONIC MUSICAL INSTRUMENT HAVING KEYBOARDS BACKGROUND OF THE INVENTION Average pulse periods of the pulse trains change by preventing the passage of a pulse of the output pulse trains'supplied from a pulse generator. The ratio of the I tain total input pulses are supplied. Consequently, the

actuations of the counter per cycle are proportional to the average pulse periods. The electric waveforms produced in the process of the actuations of the counter are amplified and then converted into musical sounds.

The electronic musical'instrument constructed and arranged in the manner described above make it convenient to produce the sounds of the musicalscales of pure temperament.

it is possible to play the electronic musical instrument according to the invention in such a manner that touching a key of the keyboard produces the corresponding sound having the same syllable name irrespective of any keys or tones by means of modulating the average pulse periods of the output pulses pro duced form a pulse generator.

it is also possible to obtain a variety of waveforms and of modulations in periodic vibrations of counters by using digital circuits herein described in detail.

The present invention is concerned generally with an electronic musical instrument having keyboards and, more particularly, the invention relates to an electronic musical instrument havingcircuits in which the waveforms of arbitrary sounds can be produced electronically.

The highness or lowness of a sound is determined by the frequencies thus the pitch is dependent on its rate of vibration.

in music there are two kinds of pitch notations: absolute pitch, which is the position of a musical tone considered in reference to the whole range of pitch or to a standard scale and determined by its rate of vibration; and relative pitch, of which musical tone' is determined by its relative position in a scale.

Table I shows the syllable names and their corresponding ratios of periodic vibrations in which both major and minor keys of pure temperament have the same key-note. Do-sharp is positioned between notes do and re, fa-sharp between fa and sol.

Perfect Table l-Continued Ratios of Ratios of periodic periodic S liable vibrations vibrations ,lnterval ames on the on the basis of basis of key-note note sol as l as l fifth Sol 2/3 Minor sixth La in minor 5/8 15/ l 6 Ma r sixt La in major 3/5 9/l0 Minor seventh Tl In minor 5/9 5/6 Major seventh Ti In major 8/ l 5 3/!0 Octave Do l/2 3/4 The key-note in minor keys is the so-called note la, however, in the description of the invention, the keynote in minor keys is described 'as the note do, and notes re, mi, fa, etc. are followed.

Regarding the notes mi, la and ti, the pitches of major andthese of minor keys have different periodic vibrations sothat these-variations of the vibrations are shown in above-mentioned Table.

The musical scales of pure temperament are arranged in integral numbers of periodic vibrations as seen in Table l and the tones and/or sounds arranged in order of the above scales are superior to that produced by common musical keyboard instruments which are'arranged in the scales of equal temperament,

with regard to musical chords in harmony as well as to melodies.

SUMMARY or THE INTENTION It is, therefore, an object of the present invention to provide an improved electronic musical instrument by which the tones and/or the sounds of the scales of pure temperament can be easily produced.

It is another object of the invention to provide an improved electronic musical instrument in which touching a key of the keyboards produces the corresponding sounds having the same syllable name irrespective of any keys or tones.

' It is still another object of the invention to provide an improved electronic musical instrument by which harmonized chords as well as the chords that are not shown in Table I can be obtained.

It is yet a further object of the present invention to provide an improved electronic musical instrument by which correct frequencies of an arbitrary sound can be easily obtained in any keys or tones.

It is further and another object of the invention to provide an improved electronic musical instrument by which continuous sounds having arbitrary waveforms can be produced.

It is further and another object of the invention to provide an improved electronic musical instrument by which rising sounds as well as falling sounds'can be freely obtained.

it is further and another object of the invention to provide an improved electronic musical instrument by which variations in the pitch of the sounds such as vibrato and portmento can be arbitrarily and correctly obtained.

it is further and another object of the invention to provide an improved electronic musical instrument with the accompanying drawings in whichlike reference numerals andcharacters designate corresponding parts andelements throughout the flguresand in which I BRIEF ascarrriou oa he aawmos FIG. 1 shows logic symbols and thetruth tables of digital circuits which employ binary numbers in digital form.

FIG. 2(a) is a schematic circuit diagram showing a preferred form of the circuit having aconventional bi: nary counter in which flip flops are connected together in cascade. FIGS. 2(b) and (c) are blockdiagrams of FIG. 2(a). I

FIG. 3(a) is a schematic circuit diagram showing a preferred form of the reversible binary counter having exclusive OR circuits and. FIG. 3(b) and (c) are block diagrams of FIG. 3(a) respectively.

FIG. 4(a) is a schematic circuit diagram having a digital comparator. FIG. 4(b) is a block diagram of FIG. 4(

FIG. 5(a) is a schematiccircuit diagram in which at least one pulse of some pulses is prevented to pass. FIG. 5(b) is a block diagram of FIG. 5(a) and FIG. 5(c) is that of the inner part of the shown dotted lines of FIG.

FIG. 6 is a block diagram having two parts of MOs shown in FIG. 5(a). The output of the MI is so arranged to connect the input of two M05 in 'a parallel.

FIG. 7 is a principle circuit diagram showing an overall electronic arrangement of the musical instrument according to the present invention.

FIG. 8 is a block diagram showing a preferred form of the connections of the switches connected with both to the keys of keyboards shown in FIG. 7 and to the circuit.

FIG. 9 is a circuit having a pulse generator 0-0 of which frequencies are settled are not to be modulated. Average pulse periods provided to a circuit .N-l are modulated by both the pulse generator G-0 and a circuit N-4.

FIG. 9a is a schematic circuit diagram showing another preferred form of a circuit in which pulse trains for making harmonic musical scales of pure temperament can be produced.

FIG. 10 is a circuit in which varieties of waveforms can be made. a

FIG. II is a schematic circuit diagram showing another preferred form of a circuit in which varieties of waveforms can also be made.

FIG. 12 shows relationship between a characteristic of a the input and output of nonlinear circuit and its waveforms.

FIG. 13(a) is a circuit in which decrement waveforms are obtained and, FIG. 13(b) shows its waveform.

FIG. 13c is a schematic circuit diagram showing another'preferred form of the circuit in which decrement waveforms are also obtained.

FIG. 14 is a schematic circuit diagram in which a continuous glide effectiveness of sounds such as portmento is produced.

FIG. 15 is a circuit for producing slight and rapid variations in the pitch of the tone such as vibrato.

FIGS. l5(a) and 15(b) are block diagrams having a circuit for producing the sounds and/or tones which have a depth as well as an expression of mixed feelings.

FIG. 16 is a circuit inwhich a variety of sounds in pitch aswell as many numbers of sounds can be producedat the same time.

FIGJI'I isa'circuit' n which pluralities ofharmonized sounds to a melody can be produced.

FIG. 18 is a circuit in which three chords can be produced.

DESCRIPTION OF THE PREFERRED EMBODIMENT Reference is now made to the drawings, first to FIG.

1 illustrating logic symbols and thetruth tables of digitalcircuits which accept binary numbers in digital form and employ-some form of a binary number system. Here represented are high level voltage (referred to as H) and lowlevel voltage (referred to as L). The inputs of the AND gate circuit and the OR gate circuit shown respectively in FIGS. 1(a) and 1(b) are not limited to just two inputs. When necessary, aplurality of inputs maybe employed. Thesmall circle shown in the logic symbol of the inhibit gatecircuit of FIG. 1(d) indicates an inverter.'0utputvoltage of the .l-K flip flop shown in FIG. 1(a) are variable'when the input voltage to CF changes from a high-voltage conditionto a condition.

.When the input voltage toy] or K is always at a high level, these symbols will be omitted in the specification.

'The output voltage of the flip flop changes to a lowvoltage condition at the instant anyhigh level voltage is suppliedto a reset terminal R. On the other hand, when the voltage supplied to the reset terminal R is kept at a low level,'the symbols of the reset terminal will be omitted.

FIG. 2(a)-is a schematic circuit diagram showing a preferred form of a circuit having well-known binary counter inwhich flip flops are connected together in cascade.FIG. 2(b) is a block diagram of FIG. 2(a). The

symbol R written in a box of FIG. 2(b) shows that the output voltage of the flip-flops change to a reset condition (the output voltageQ from four flip flops is in a low-condition) at the instant the high level voltage is supplied to'the reset terminal R. The number 5, written in the left bottom of the box explains that the counter turns to a reset condition every five pulses when inputs supplied to theterminal are in high-volt conditions. The number 16, written in an upper portion of the box of FIG. 2(b), shows that the outut voltage. of the flipflops turns to a reset condition every sixteen pulses when inputs supplied to the terminal R and to the part ,where the number 5 is written are at a low level voltage. The output of the voltage will be written at the right-side ofv the box of FIG. 2(b). Output lines connected to numbers with a circle, for example,@,,@ ,are the output Qfrorn the flip flops. FIG. 2(a) is a block diagram showing these output lines.

When the output Q of the flip-flop is in a high-voltage condition, the logic state will be designated as l, and when it is in a low-voltage state, the logic code will be 0. These binary codesof the logics are in order from that of the last flip flop and, are referred to as the indicated numbers of the counter I. The indicated numbers show the number of pulses which are supplied to the counter after it is reset.

the box of FIGS. 2(1) and (e) as the numbers bearing,

no circle. g

The numbers indicated by thecounter in FIG. 2 increases every time a total number of input pulses are supplied to it. When a maximum number is reached, the counters are reset to zero. Reversible counters are also well-known in the state of the'art. These counters will increase until a maximum number of pulses-have been counted and thenv decrease until'a minimum has been reached.

FIG. 3(a) is a schematic circuitdiagramshowin'g a 15 preferred form of the reversible counter having Exclu-v sive OR gates E-I toE -S inwhic indicated numbers increase when the outputvoltage from the-flip flop connected subordinately-lastly is in the low level. Conversely, the indicatednumbers will decrease when the 2 above-mentioned output voltageis at the high level. FIGS. 3(b) and (c) are block diagrams of FIG. 3(a). The required number of input pulses forthe counter to return to a reset condition is twice the number shown between the arrows.

FIG. 4 is a schematic circuit diagram of a preferred form of a digital comparator circuit. It is known that output voltage actuated by thedigital comparator varies at a high or low level corresponding to binarynumbers in digital form. As illustrated in FIG. 4(a), the output voltage from the OR gate 'circuit OR-2 changes in a low level condition and the flip flop F-5 composed of two AND circuits A4 and A-5 are reset, and the output voltage from the flip flop changes at a low level. This takes place when the indicated numbers of the counter C-l are varying rapidly as compared with the indicated numbers of the counter C-2, and then numbers of the last five bits of the counter C-l are equivalent to the indicated numbers of the counter G2. The flip flop F-5 is set when the number in counter G1 is 32. However the flip flop can not be reset while the counter (1-! 'indi FIG. 5(a) is a schematic circuit diagram having a circuit in which a pulse of the pulse trains is prevented to pass due to the operation of the counters. As illustrated in-the drawing, a pulse supplied to the counter is pre- 5 vented to pass through an AND circuit A-l3, for example, an input line M is in a high-volt condition and when the counter C-3 indicates that its numbers are 3, 7, II and 15. Thus a pulse train of four pulses is preventtd to pass.

l0 When input line I-S is in a high-volt condition, the

output from an OR gate circuitOR-4.turns to be at a high-levelwhen the counter indicates that the number is Qor ll despite input lines l-2, I-3 and I4 being in the low-voltage-conditions.

t The inputpulses supplied from aninput line 1-10 pass through the counter C-3. Consequently, if the output 0 from thefflip flop F56 isin a low volt1condition the next 'pulsefispreventedto passflthrough the AND circuit 0 A-l4.'I-loweve r",-if the a output Qof aflip flop F-6 is in a high-volt condition, then following sequence of pulses can pass through the AND gate circuit A-l4. Thus, a pulse is prevented" to passIthrough the AND circuit A-l4 when the next condition of counter 03 is at a 25 high level.

This also means that a pulse prevented to pass through the AND circuit A-l4 can not pass through the counter.

, Table 2 shows the actuation of the counter C-3 and 30 the conditions of prevention of the passage of pulses 40 lines of the box of FIG. 5(b), the fractionary number's are also the ratios of the average pulse periods when the input lines shown below are in high-volt conditions.

One MO or more MOs which do not prevent the passage of the input to the counter can be connected to the 5 only one MI. I

Table 2 Numbers 0 ulses rum 1 reset Numbers Numbers eondio of tion of pulses pulses the pulled pulled counter out b out I? to the Al A-l Ratios In ut lines next Indicated numbers during Indicated numbers during of wh ch are in reset by 03 when a one by GE when a one average high-volt condlpulse is pulled complete a pulse is pulled complete pulse conditions lion out by A-l4 cycle out by A-l3 cycle period I-9 l6 0 l-a I6 3 l l6/l5 l-5. I-9 l6 4. l2 2 9/8 H. l-S. 1-9 5 4 I 6 5 H. M 5 3 l 5/4 I-7 l6 3. 7. ll. l5 4 4/3 H. H. L) 5 2. 4 2 7/5 l-3. l-9 l6 0. 2. fi. 6i}, l0. 8 3/2 H. I-2. L9 5 0. I. 3 3 8/5 H. H5 5 1,3 2 5/3 1-1. M. L9 5 0. l. 2, 3 4 9 5 M. 1-9 l6 0 l. 2. 3. 5, 6 l4 l5/3 7, 8, 9, 10. It. l3. l4. l5 I-o I6 I. 3, 5. 7. 9. 8 2

II. I I5 FIG. 6 is a block diagram having two MOs shown in FIG. (a). The output of the Ml is connected to the two MOs in parallel.

FIG. 7 is a principal circuit diagram showing an overall electronic arrangement of the musical instrument according to the present invention. The frequency of obtained when switches 8-1 to 8-6 are connected with the opposite side of the lines of the above. The chropulse generator G will be modulated. A circuit N-l actuates a pulse to be absorbed. The voltage of the lines connected to keyboard K is at a low level when the keys are not touched and, at a high level when the keys are touched. Pulse trains ofa pulse period which are in proportion to the ratio of the fructionary number conncctcd to the line, are consequently obtained when the line is in a high-volt condition. The pulse trains are passed to a cycle counter C-4 when an input line H! is in a low-volt condition.

After 240 total input pulses, the counter 04 will return to the reset condition and the waveforms obtained are altered, filtered. and widened into ideal'forms by OUT-1. The wave forms are then converted into sound. The pulses which are being counted with the 240 total input pulses, are thus 240 times longer than that of the average pulse period of the pulse trains in which a pulse is absorbed. As shown in Table l, the average'pulse period of the pulse trains produced when the keys are touched is in proportion to the cycle per second of the sounds of the scales. Thus it should be noted that touching of the keys makes the pure temperament sounds of the musical scales (do-sharp has a slightly different ratio of the sound). if twelve keysare further provided and one of the keys are touched, the output pulse trains from the circuit N-l pass through a flip flop F7 and the average pulse period becomes twice as long when the input line which is connected to the key touched of the lines connected to the circuit N-l, and the input line 1-1] are both in high-volt conditions. Thus the counter 04 actuates completely every time 480 total output pulses and the sound of a one-line lowered octave can be obtained from OUT-1. if additional flip flops are used, sounds of more lowered lines of the octave can be obtained.

Modulations of the cycle per. second of pulses produced by the pulse generator G corresponds to the modulation of the cycle per second of sounds produced from OUT-l. This modulation does not affect the ratios of the cycle per second of sounds. Thus, one can play in any keys or tones by modulating the frequency of the pulse generator G.

As illustrated in FIG. 7, the electric waveform obtained after 240 input pulses has exactly the same ratio irrespective of a touched key if the pulse generator 0 provides the same pulse period of the pulse trains. if for example, the counter actuates completely after 256 input pulses, the electric waveform thus obtained will not have exactly the same ratio. However, we can hear the thus obtained sounds as the same sound of which cycle has the average 256 input pulses.

The more numbers of pulses the cycle counter C-4 requires, the fewer the difference of period the counter will take for one complete cycle. The average period the counter takes from a reset condition to the next reset condition will be referred to as cycle.

FIG. 8 is a block diagram showing a preferred form of the connections of the keys of the keyboards with the circuit N-l. Sounds of major keys are obtained when switches 8-1, 8-2, to 8-6 are connected with the lines as shown in FiG. 8. Sounds of minor keys are matic keys of keyboards produce half higher sounds than the keys positioned in the left sides. in this case, the chromatic keys of keyboards should be placed all between the keys for common tones and consequently the keys for use in the key-noteare difficult to distinguish. Thus the keys of the above key-note or the keys for use in notes do, mi and sol are so colored or constructed of other shapes as shown in the Figure to solve the aforementioned problem.

H0. 9 is a block diagram having a pulse generator 0-0 of which frequencies are not modulated. Average pulse periods provided to the circuit N-l are modulated by the circuit N-4. For instance, when a key G of a keyboard K-3 (-having key or tone names A to G-) is touched, the pulse trains from the pulse generator 0-0 are provided to thecircuit N-l as an input-voltage. If key C ofthe keyboard is touched, the pulse trains of a 3 second longer average pulse period are provided to the circuit N-l. On the other hand, about sixteen fifteenth (and/or l35/l28 average pulse period is provided in case that switches S-7 to 8-13 are set to the left lines, and approximately fifteen sixteenth (and/or 25/24) average pulse period may be provided if switches S-7 to S 13 are set to the right lines. Thus, keys or tones in the A- to range are obtained when the switches are turned to the left, and keys or tones in the A- to G-sharp range are obtained when the switches are turned to the right.

ln this method as illustrated in FIG. 9, frequencies of the pulse generator G0 are settled and not to be modulated. Crystallized quartz may be used to stabilize the frequencies of the pulse period so that the correct sounds in any keys or tones can be obtained without any. difficult tuning.

FiG. 9ashows another preferred form of a circuitin which pulse trains for making the musical scales of pure temperament can b'e"produced. The circuit N-4 which sets a key or tone is connected together with the circuits N-l-l, N-l-ll and N-i-lll which set the musical scales. MOs, connected to each of these circuits can be used in stepping down the produce frequencies. Table 3 shows the combinations of the input of MOs and the input of Mls for producing the sounds of pure temperament.

, if, for example frequency of the pulse generator 0-0 is 608 KHz or l2l6 KHz, the key G is produced when any pulse of the above is not absorbed. The note sol of the highest line of the octavecanbeobtained if none g of the 256 total input pulses areabsorbed'The sound produced by pianos.Various kinds of modification are quencycan be-Ihighe rg-than.the hove.mentioned fre-i quency and that more-numbers of total inputpulsesfor a; f t n the cycle can bepro'vided to btai" a v quality and soundsiyi: I i I In the musicalinstrumenthavin a preremaron fi r the'circuit as illustrated 'in":FiG',jf 7fbrElQ. 8, a key (or; tone is determined by theQCycIe'perfsecon'd or;average.

pulse period of the pulses supplied from thepulsegenerator G. This would facilitate the playing of the instrument since the sound of the samefsca'le'fcanbe pro- 3 duced in any keys ortone'sby using samekeys of key boards.

Various advantages of the electronic"musical'instrument according to theppresent invention will become apparent by applyingthe principlesfofthe invention.

waveforms with theoutput of thecycle counter.

FIG. 10 showsa preferred :formf'of' theabove-d' '25 mentioned circuit. If the cycle counter C-4 is composed of a binary systemed counter, the indicated numbers of five bits counted from the number positioned at thetop flow into the output portions OUT-2 and are converted into a code of the numbers of six bits in binary form by a code converter CC. The code then converted into a proportional analog voltage'by a digital-analog converter D-A. Thus. staircase waveforms having 32 stair steps per cycle are produced. vSince the height of each stairstep is determined by the code of the code converter CC, arbitrary 32 waveforms per cycle can be produced.

I v. l

COM keepsthe'circuit in a high-voltage condition while'the-indicatednumbers of the counter 04 are larger'than the numbers of the counter C'-6. The output ,of thejcornparato rfCOM becomes-a low-volt condition As shown in FIG; 130. th

when the indicatedlnurnbers of I the counter 04 are ,smaller than the numbers of the counter C 6. Thus. the .outpu't ;of" th' e;.cor nparator COM-1' becomes shorter as ef' iridicated -n sr2 1er lcounter C 6 beco me anger. This produces the" wavefo rrns illustrated in" FIG.

i(b The;wave'formsfarelfiltered-by a Iow pass filter and .converted intdisoundsil-Tht-i widerwaveforms are converteda.into loudersounds andjthe narrow' wavefo'rmsinto softerjsoundss, :5 1..

p finput of counter 0 6 is connected-to-the output of a thirdcounter C-l0. The

input of this counter C 10 is connected to the output of the 'comparator CQMJand theinput of the cycle 0 .counter- C-M The-comparator COM-'1. compares the p tsof counters-C54 and C- 6. 1

Various kindszof sounds can be produced by changn ingtheperiods" of pulses whichare supplied to the One of the advantages is to make various kinds of i FIG. mans a blockdiagrarn in wat hin code converter CC and-the"-digital analog-converter DA-l.

shown .inFIG. ll. produce arbitrary waveforms. The

voltage produced by the digital analog converter DA-2 corresponds tothe ratio of the complement of the indi- If more numbers of stairsteps per cycle are required,

more numbers of bits coming from the cycle counter 04 should be supplied. If more ideal height of each stairstep is required. more numbers of bits converted by the code converter CC should be produced.,OXof the OUT-2, shown in FIG. 10, in circuit in which amplifying of the pulse-width. filtering of the waveforms and conversion'into sounds occurs.

FIG. 11 illustrates another preferred form of a circuit in which-arbitrary waveforms are producedby the outcated numbers of the counter C-6. The waveforms produced by the digital-analog converter DA-I are modulated by the this obtainedv voltage. Modulation of the above is madeby the known technology.

As shown in FIG. 13c, theinput of the modulator MOD is connected to the outputs of two digital-analog converters DA-I, DA-Z. The output of this modulator is connected to an analog-sound converter 0X.

FIG. 14 is a's'chernatic circuitfor producing a continuous glide'effect' of sounds. 'such' as portmento. the pulse trains of an input line l-I3 become the input the of cycle counter. C-4whenthe indicated numbers of the counterC-7 aresm'aller than indicatednumbers of last six'bits of the counter 04. The-.pulse'itrains'ofan input line I914 becomethe' input ofthe counterC- d when the put of the cycle counters. A counter C-'5 is connected in cascade with a reversible counter RC-I and the |ndi- 'J cated numbers of the reversible counter are convened into an analog voltage.

to a digitai-analog converter DA Z'which' produces i The output from the reversible-counter R01 is fed staircase waveforms-having 64 steps. The staircase waveforms are then filtered and converted into saw FL. Cycles of the sawtooth tooth waveforms by a filter waveforms correspondto the ratio-ofan'average input pulse period tojthe cycle counter C-5 and theampli! tude of the sawtooth waveforms are not modulated in any musical scale. The sawtooth waveforms pass through a nonlinear circuit NI. which modulates the waveforms.

FIG. I2 illustrates the produced waveforms by the nonlinear circuit NL.

FIG. 13(0) is a schematiccircuit diagram having the cycle counterC-4 as well as another counter G6 in which an indicated number changes more-slowly than that of the counter C-4. The output of a comparator.

I indicated numbers .of the counter 1C-7 is equivalent to or larger thanithe'numbers ofgthe last six bits of the counter .C-4.=The;pulse 1trains .of both the input lines l-l3and [-14worleinmanyfshifts per cycle of asound.

Thuslthe cycle-counteriC-t has returned to the-reset condition after;' 256 total: input pulses which are supplied from input lines il 3 .andI-M.

FIG. lsis aschematic showing a pre- 'ferred 'form@ of a"cir cuit for periodic variations in the pitch of sounds. suchas-vibrato. Indicated numbers 01 the revers'iblejcounter RC-Zincrease every time a pulse is supplied to theiinput'IineI-IGand-the input line H5 is in'a high volt condition. When its reversible counter RCQZ reaches the maxirnum..theincrease stopsbecausz the output ofan exclusive ORJcircuit E- I I, changestr a low-volt'condition.indicated numbers of the revers Ible counter RC-2 decrease one. by one when the inpu line [-18 is in a low-volt condition. and the dCCI'CEISt stops when theindicatednumbers of the reversibh counter RC-Z reaches the minimum. Thirty one pulse are requiredfor thecycle actuation of the counter C-l whenthe;indicatednumbers'of'the reversible counte 'RC-Z-are larger than' theindicated numbers of th counter C-9. Counter C-8 returns to its cycle actuation after thirty two pulses when theindicated numbers of the reversible counter'RC-Z are smaller than or are equivalent to the indicated numbers of the counter G9. I Thus, the number of input pulses required for the cycle actuation of thecycle counter C4 aresubtracted by the indicated number or numbers of;thejreyersible counter RC-2, and the sounds thus producediare' high-. pitched. As illustratedin' EIGLJS, the f'counter'IC-4 has periodic variationsin the fpitch of tones, such as..vibrato, can be produced by changing the conditio'ns of the input line 1-15 at a high voltage or at "a low. voltage hand. v

By producing slightly different pitch sounds, FlGS.

(a) and 15(b) produce a sound having a depth and lorexpress mixed feelings. Aslshown'in FIG. 15(0), if-

the pulse trains required for the cycle counters C-4 and O5 to return to the reset conditions are slightly different in number, the sounds produced from thecounter When a signal from the ke'ypasses through the inhibit I gate A 15, other. signals from the key are prevented to pass throughboth inhibit gates A"-23.and A-Sl. There are three groups in thefFigurezGroup 1 includes the cirfcuits A-IS toA-ZZt Group llincludesthe circuits A-23 6 latso and Group lilthe circuits'A-SI to A-38. In this arrangemenhiffa keyisitouched, .thesignal of the key is provided fto' the circuit- N51 passing through one of theinhibitjg'atecircuitin the'Groupl and the signal doesnotfpass'through thefigates' of the Group II or ill. if another keyisztouched at the sametime the first key' is'bei'ng pressed, the. signal from this second key is provided to thecircuit N-Zpassing through the gate of the group ll.jln this way, the circuitsN-l, N-Z-and N-3 actuate to. produce sounds corresponding to keys which are'fdepressed atthe'same time'oThe keyboard K-4 has v w eight keys and only three soundscan be produced at a by means of the cycle of vibrato automatically,- orby H boardsand, more numbers 'ofsounds can be produced C-4 and that from the counter C-S willhave a slightly different pitch. The cycle counter C-4 returns to the reset condition after 256 pulses'and the cycle'counter 05 returns to the reset condition after 259,lpulses. Consequently the sounds produced from" the counter C-4 and that from the counterC-S have a slightly diftime in the circuit shownin HQ. 16. However, it is apparent that 'more'variety of sounds in pitchcan be profduced'at' by equipping more numbers of keys of keysimultaneou'sly-byarranging more numbers of the gate groups and the circuits such as N-l to N-3 of the above.

. no.1? isaschematie circuit diagram having another preferred-formof a circ'uitin whicha keyboard K-2 is used for sounding the notes of the scales of a main melody. The output pulse trains of which average pulse periods correspond to a toughing key. of the keyboard K-2, are produced from a circuit N-l. Akeyboard- K-5 is so arranged that two lowered sounds in pitch than the ferent pitch corresponding to the ratio of 2 $6 to 259 a FIG. 15(b) is a schematic circuit diagram showing another preferred form of a circuit in-which slightlydifferent sounds in pitch can be produced. An inhibit'gate circuit A-38 is connected with the cycle counter 05 which returns to the reset condition after the same total sounds-from the keyboard K-Z can be produced simultaneou'sly withjthe soundsfrom the keyboard K-Z. One of'the output'pulsesjis pulled out-by a circuit N-4 by touching a key of the keyboard K-S AVerage pulse periods'of the output pulses from the circuit N-4'are six/- input pulses as the cycle counter C-4 does. Thus, a

pulse of 60 pulses or a pulse of 120 which are provided to the inhibit gate circuit A-38 is prevented to pass.

Two different sounds are in harmony if the two sounds are in scales of pure temperament andtheir periodic vibrations are in simply proportional each other.

fifth times or five/fourth'times as long as average pulse 2 periods of the output pulses from" the circuit N-l.

When the touching keys of the keyboard K-Z are mi in major, laj ln major and ti in major respectively, aver- 40 age pulse periods of the output produced by the circuit But in FIG. 7, only one sound is produced if two keys of the keyboard are touched at the same time. Therefore, the circuit as shown in FIG. 7 is not apreferred form with regard to theabove and, the circuit shown in FIG. 16 covers the disadvantage of the circuit in FIG.

Reference is now made to FIG. 16 which illustrates a circuit arrangement having selective circuits between a keyboard K-4 and the circuits N-lto N93. When more than one key of the keyboard K4 are touched at the same time, one signal-from a key of the keyboard K-4 is provided to the circuit N-l, another signal from another key to the circuit N-Z, the other signal from the other key to the circuit N-3. ln order to bebrief, the arrangement of the Figure 14-4 as well as the circuit NJ to NJ.

in the above drawing, the samesignsof the same numerals are marked with a double circlev to show that they are connected to each other. inhibit gate circuits A-lS to A-38 which areconnected with thekeys and with the circuit N-\ to N3 actuate ltoj-pass a signal when no signal input is supplied in a high-volt condition. For example, the inhibit gate circuits A-15,;A-23 and A-3l are communicated each other via are. key.

has eightkeys of the keyboard I N4 are tive/fourth times respectively as long as the average pulse-periods of-each'of theknotes of the above circuitN-l by touching-thekeys-of the keyboard K-S. in this case,-1average pulse periods of other notes ofthe --above circuit are six/fifth times as long respectively.

A. keyboard. K- 6 is so; arranged that five lowered sounds in pitch than the sounds from the keyboard K-Z can be produced simultaneously. with the sounds from the keyboard K-Z. The output pulse trains of which averagepulse periodsfare five/thirdtimes or eight/fifth times aslong asthat from the circuit N-hare produced 'fr om;the' eircuitjN-S, when touching keys of the keyboard -K-2 -are -re, mi, lain major. and 'si in major, average pulse periods of th e'output-produced by the circuit N-S are five/third times as long as the average pulse periods of each'notes of-these in thecircuit N-l. Average pulse periodso'f other notesabove-described are eightlfifthtimesas long respectively.

Threesounds which are different from each other in pitch-are produced from the output pulse trains of the circuit N-l, N-4 and N -'5 Periodic vibrations of the three sounds are in proportion to-the averagepulseperiods of the circuit N-l, N-4 and N 5. respectively.

These three sounds can be producedby providing the three cycle counterswith-the oututipulse trains from the circuit N'lyN" and N-S. Theymay return to a res'etcondition after the sametotal input pulses in numher. Thus, the sounds in harmony with a main melody can be producedat by the process described above. These sounds are more in harmony with the melody than the sounds which 'areobtained bystriking the same notesof the scales of equal temperament arranged in the common keyboard musical instrument. It is apparent that the'sounds produce'd in-the process above described are notlimitedto twoor fivellower ed sounds in pitch, but is covers any of different sounds-in pitch.

FIG. 18 is a schematic circuit diagram showing a preferred form of a circuit in which'three chords can be.

The output pulse trains of the circuit N-4 are pulled out by circuits N-l, N-6 and N-7 and becomethree D-l, the average pulse periods are twice the number of what they are..The output does not step down by the circuit D-2 in this case. Thus. the average pulse periods of the output pulse trains from the OR gate circuits R-6 and OR- 7, andthe-circuit N-7 become three :times. twice and twelve/fifth times respectively as long aswhat they are and are converted into sounds by cot'nting the .same -numbers by the counters. The sounds'produced are, if the sound converted from the outputof the circuit N- 4 is settled to be the note sol. one-line lowered do'in octave, one-line lowered sol in octaveand one-line lowered mi-in octave. The three chords composed of the notes do, mi and sol can be thus produced. 5 Table 4 shows the ratios of increases of the pulse periods at the output voltage in the three circuit for pulling but a pulse and in the two circuit for stepping down of the frequencies, .lt also shows the syllable names produced in the process as mentioned above. (The sound 0 convertedfrom the output, of which pulse does not kinds of pulse trains with different pulse periods. D-'l' being pulled out. providedby the circuit N-4 is settled to be the note sol.)

Table 4 Ratio of increase of average Ratio of pulse pulse periods and periods Output pulse arranged in order provided riods of from longer one by by by by by R-6. OR-7 of the left N-l N-6 N-7 D-l D-2 and NJ column Syllable names 3/2 4/3 8/5 2 l 3 2 l2/5 3/2 6/5 i do mi in sol ms or 9/8 4/3 8/5 2 2 9/4 3 8/5 3/2 9/8 4/5 do fa j in in mayor l 4/3 8/5 I l 1 4/3 8/5 8/5 4/3 I si in re sol ma or 3/2 4/3 5/3 2 l 3 2 5/2 3/2 5/4 t l do in sol minor 9/8 4/3 5/3 2 2 9/4 '3 /8 3/2 9/8 :.l5/l6 do fa la in minor l 4/3 5/3 I l l 4/3 5/3 5/3 t 4/3 l si in re sol minor l 8/7 8/5 I l l 8/7 8/5 8/5 8/7 l I si fa sol is a circuit used in the step-down of frequencies. When an input line H7 is in a low level condition, the output of the circuit D-l is in the same average periods as the output of the circuit N-l. When the input line H! is in a high level condition. a ilip'flop F-8 steps down the frequencies of the output voltage of thecircuit NJ and the pulse trains, which are twice asiong in average period, can be produced by the cireuitD-l. A circuit D-2 has the same'arrangement as the circuit D-l. When the output voltage does not step down by the circuits D4 or D-2, the periodic vibrations of the soundsproduced by counting the outputs from the circuits D-l, D-2 and N-7 by the three counters are in proportion to the average periodic vibrations of the output pulse trains from the circuits N-l. N-6 and N-7.

When the numbers of pulses are decreased by the circuit D-l or by both the circuits D-l and 0-2, inverted chords can be produced. When a key K-7 is touched.

each average pulse period of the circuits N-l, N-6 and N-7 become three/second times four/third times and eight/fifth times. respectively what they were if that key K-7 was not pressed. Being stepped down by the circuit Three kinds of pulse trains are supplied to the three 7 counters respectively. This enables the electronic musicalinstrument to produce not onlythe chords above described but also to'produce the broken chords by vprovidingthe counters with the pulse trains periodically in order. .L i l The three chords that are described and shown in Table ,4 are limited only to the familiar. three chords, yet it is apparent'that various kinds of triads and the chords of four or moreltones are able to produce by the same method as described above.

it is apparent that the electronic musical instrument according to the present invention has the advantage of being easy for a player to play since touching a key on the keyboard produces the corresponding note of the key on the keyboard irrespective of any keys or tones. The sounds of the musical scales of pure temperament can be produced correctly in any keys or tones, various kinds of tones in pitch and 0t chords that are difficult to produce in thepure temperament are easily able to produced. Harmonized in depth sounds can be easily produced and it is possible to play the instrument by mined number greater than one determining sounds in pitch and sounds of waveforms arbitrarily. The advantages mentioned above enable an untrained player, fond of music, to learn how to play the instrument quickly and accurately.

What is claimed is:

l. An electronic musical instrument having a circuit means comprising:

. a pulse train generating means producing a pulse train having variable periodic or average pulse periods;

first keyboard having a plurality of keys corresponding to the notes of do, re, mi, fa, sol, la, and ti; second keyboard having a plurality of keys corresponding to the keys A, B, C, D, E, F and first circuit arrangement connected to said first keyboard for absorbing or pulling out a pulse of said pulse train in response to the depression of a key of said first keyboard;

a second circuit arrangement connected to said second keyboard, for modulating the periodic vibrations or average pulse periods of said pulse train in response to the depression of a key of said second keyboard;

cycle counter means for producing a waveform, in-

cluding a first cycle counter for counting the pulses absorbed or pulled out by said first circuit arrangement, and for returning to reset after a predetermined number of input pulses have been counted; and

output means connected to said cycle counter means for amplifying and converting waveform into sound, said output means including code converter means for converting the counted number of pulses counted by said cycle counter, into codes, a first digital-analog converter means for convering said codes into analog voltage and analog-tsound coriverter means for converting said analog voltage into sounds.

2. An electronic musical instrument according to claim 1 wherein said first circuit arrangement absorbs or pulls out pulses of a pulse train modulated by said second circuit arrangement.

3. The electronic musical instrument according to claim 1, wherein said first circuit arrangement absorbs or pulls out said average pulse periods in proportion to 1,819, /6, 4/5, 3/4, 2/3, 5/8, 3/5, 5/9 and 8/15 for each individual note or of second, fourth, eighth and so on powers of two and, wherein both major and minor keys having the same key-note can be produced.

4. The electronic musical instrument according to claim 1, wherein said cycle counter means further includes a second counter and a third counter for advancing a single count upon the passage of a predeterof pulses, and a comparator for comparing the counts registered on said cycle counter and said second counter and producing a high voltage-low voltage digital waveform therefrom by changing a high voltage condition to a low voltage condition dependent upon the relative magnitude of the counts, the input of said third counter connected to the output of said comparator and the input of said cycle counter, and the output of said third counter connected to said second counter.

5. The electronic musical instrument according to claim 4, wherein said output means comprises a second digital-analog converter means for converting said high voltage-low voltage digital waveforms into analog voltage, a modulator means, the input of which is connected to the outputs of said first and second digitalanalog converter means and the output of said modulator means is connected to said analog-sound converter means, for modulating said voltage.

6; The electronic musical instrument according to claim 1 also comprising:

a third keyboard having a plurality of keys corresponding to lowered steps of the notes of said first keyboard; and

a third circuit arrangement connected to said third keyboard for absorbing or pulling out pulses of a pulse train absorbed or pulled out by said first circuit arrangement in response to the depression of a key of said third keyboard.

7. The electronic musical instrument according to claim 1 also comprising:

a fourth keyboard having a plurality of keys corresponding to the chords of the notes of said first keyboard; and

a fourth circuit arrangement connected to said fourth keyboard for absorbing or pulling out pulses of a pulse train absorbed or pulled out by said first circuitarrangement in response to the depression of a key of said fourth keyboard.

8. The electronic musical instrument according to claim 7, wherein, when an average pulse period of the output pulse/trains from said pulse generating means is designated as l, the pulse trains of three kinds of average pulse periods selected from the average pulse periods are produced in proportion to l, 9/8 or 3/2 for the first, 8/7 or 4/3 for the second, and 8/5 or 5/3 for the third said pulse train.

9. The electronic musical instrument according to claim 1 wherein said first circuit arrangement comprises a plurality of circuits and selective circuits equipped between said circuits and said first keyboards for supplying the signal produced from touching a key to oneof the plurality of circuits, for preventing said signal from being supplied to other of said plurality of circuits for ensuring that a circuit provided with a signal from touching one key of said first keyboard will not accept other signals from touching another key of said keyboard.

10. An electronic musical instrument having a circuit means comprising:

a pulse train generating means producing a pulse train having variable periodic or average pulse periods;

a first keyboard having a plurality of keys corresponding to the notes of do, re, mi, fa, sol, la, and ti;

a second keyboard having a plurality of keys corresponding to the keys A, B, C, D, E, F and G;

a first circuit arrangement connected to said first keyboard for absorbing or pulling out a pulse of said pulse train in response to the depression of a key of said first keyboard;

a second circuit arrangement connected to said second keyboard, for modulating the periodic vibrations or average pulse periods of said pulse train in response to the depression of a key of said second keyboard;

cycle counter means for producing a waveform including a cycle counter for counting the pulses ab- 

1. An electronic musical instrument having a circuit means comprising: a pulse train generating means producing a pulse train having variable periodic or average pulse periods; a first keyboard having a plurality of keys corresponding to the notes of do, re, mi, fa, sol, la, and ti; a second keyboard having a plurality of keys corresponding to the keys A, B, C, D, E, F and G; a first circuit arrangement connected to said first keyboard for absorbing or pulling out a pulse of said pulse train in response to the depression of a key of said first keyboard; a second circuit arrangement connected to said second keyboard, for modulating the periodic vibrations or average pulse periods of said pulse train in response to the depression of a key of said second keyboard; cycle counter means for producing a waveform, including a first cycle counter for counting the pulses absorbed or pulled out by said first circuit arrangement, and for returning to reset after a predetermined number of input pulses have been counted; and output means connected to said cycle counter means for amplifying and converting waveform into sound, said output means including code converter means for converting the counted number of pulses counted by said cycle counter, into codes, a first digital-analog converter means for convering said codes into analog voltage and analog-tsound converter means for converting said analog voltage into sounds.
 2. An electronic musical instrument according to claim 1 wherein said first circuit arrangement absorbs or pulls out pulses of a pulse train modulated by said second circuit arrangement.
 3. The electronic musical instrument according to claim 1, wherein said first circuit arrangement absorbs or pulls out said average pulse periods in proportion to 1, 8/9, 5/6, 4/5, 3/4, 2/3, 5/8, 3/5, 5/9 and 8/15 for each individual note or of secOnd, fourth, eighth and so on powers of two and, wherein both major and minor keys having the same key-note can be produced.
 4. The electronic musical instrument according to claim 1, wherein said cycle counter means further includes a second counter and a third counter for advancing a single count upon the passage of a predetermined number greater than one of pulses, and a comparator for comparing the counts registered on said cycle counter and said second counter and producing a high voltage-low voltage digital waveform therefrom by changing a high voltage condition to a low voltage condition dependent upon the relative magnitude of the counts, the input of said third counter connected to the output of said comparator and the input of said cycle counter, and the output of said third counter connected to said second counter.
 5. The electronic musical instrument according to claim 4, wherein said output means comprises a second digital-analog converter means for converting said high voltage-low voltage digital waveforms into analog voltage, a modulator means, the input of which is connected to the outputs of said first and second digital-analog converter means and the output of said modulator means is connected to said analog-sound converter means, for modulating said voltage.
 6. The electronic musical instrument according to claim 1 also comprising: a third keyboard having a plurality of keys corresponding to lowered steps of the notes of said first keyboard; and a third circuit arrangement connected to said third keyboard for absorbing or pulling out pulses of a pulse train absorbed or pulled out by said first circuit arrangement in response to the depression of a key of said third keyboard.
 7. The electronic musical instrument according to claim 1 also comprising: a fourth keyboard having a plurality of keys corresponding to the chords of the notes of said first keyboard; and a fourth circuit arrangement connected to said fourth keyboard for absorbing or pulling out pulses of a pulse train absorbed or pulled out by said first circuit arrangement in response to the depression of a key of said fourth keyboard.
 8. The electronic musical instrument according to claim 7, wherein, when an average pulse period of the output pulse trains from said pulse generating means is designated as 1, the pulse trains of three kinds of average pulse periods selected from the average pulse periods are produced in proportion to 1, 9/8 or 3/2 for the first, 8/7 or 4/3 for the second, and 8/5 or 5/3 for the third said pulse train.
 9. The electronic musical instrument according to claim 1 wherein said first circuit arrangement comprises a plurality of circuits and selective circuits equipped between said circuits and said first keyboards for supplying the signal produced from touching a key to one of the plurality of circuits, for preventing said signal from being supplied to other of said plurality of circuits for ensuring that a circuit provided with a signal from touching one key of said first keyboard will not accept other signals from touching another key of said keyboard.
 10. An electronic musical instrument having a circuit means comprising: a pulse train generating means producing a pulse train having variable periodic or average pulse periods; a first keyboard having a plurality of keys corresponding to the notes of do, re, mi, fa, sol, la, and ti; a second keyboard having a plurality of keys corresponding to the keys A, B, C, D, E, F and G; a first circuit arrangement connected to said first keyboard for absorbing or pulling out a pulse of said pulse train in response to the depression of a key of said first keyboard; a second circuit arrangement connected to said second keyboard, for modulating the periodic vibrations or average pulse periods of said pulse train in response to the depression of a key of said second keyboard; cycle counter means for producing a waveform Including a cycle counter for counting the pulses absorbed or pulled out by said first circuit arrangement, and for returning to reset after a predetermined number of input pulses have been counted, said cycle counter means further including a reversible counter means for incrementally increasing from a preselected minimum number until a maximum number is reached, said cycle counter being connected in cascade with said reversible counter means; and output means, connected to said cycle counter, comprising a digital analog converter which converts the counted number of pulses into analog voltage, a filter to filter said voltage and to produce sawtooth waveforms, a nonlinear circuit to modulate said sawtooth waveforms, and analog sound converter means for converting said waveforms into sound. 